Engineering Commons^™

Simulations Of Transient Membrane Behavior In Cells Subjected To A High-Intensity Ultrashort Electric Pulse, Q. Hu, S. Viswanadham, R. P. Joshi, Karl H. Schoenbach, Stephen J. Beebe, P. F. Blackmore

Bioelectrics Publications

A molecular dynamics (MD) scheme is combined with a distributed circuit model for a self-consistent analysis of the transient membrane response for cells subjected to an ultrashort (nanosecond) high-intensity (approximately 0.01-V/nm spatially averaged field) voltage pulse. The dynamical, stochastic, many-body aspects are treated at the molecular level by resorting to a course-grained representation of the membrane lipid molecules. Coupling the Smoluchowski equation to the distributed electrical model for current flow provides the time-dependent transmembrane fields for the MD simulations. A good match between the simulation results and available experimental data is obtained. Predictions include pore formation times of about 5-6 …

Programmable Process Flow Networks, Filip D. Cuckov

Electrical & Computer Engineering Theses & Dissertations

A model that introduces programmability to processes occurring in a cargo terminal simulation through the use of a process language is presented in this thesis. The model provides a means for a straight-forward definition, and redefinition of changing processes, their incorporation in the simulation architecture and efficient execution. The model was built to investigate a solution for transforming the cargo terminal simulation CPortS into a process-oriented simulation without hard-coded processes. The approach taken separates the system into an architecture and a set of processes which utilize and interact with the architecture's resources and infrastructure. The processes that take place within …

Creating Software [Sic] Environments On An M-Node Beowulf Cluster To Execute Discrete-Event Simulations, Jermaine Fitz-Gerald Headley

Electrical & Computer Engineering Theses & Dissertations

This thesis describes the development of a software tool that facilitates the creation of software environments that make a simulation tool execute k replications of an application program on several nodes of an M-node Beowulf cluster. It is assumed that each cluster-node consists of p processors. The p processors that are contained in the master cluster-node are termed master processors, and the p processors that are contained in a slave cluster-node are termed slave processors. The slave processors are used to execute the replications, while the master processors are dedicated to schedule the replications and process other housekeeping chores. For …

Rapid Prototyping For The Design Of Virtual Worlds, Prabhu V. Krishnan

Electrical & Computer Engineering Theses & Dissertations

Development of Virtual Reality (VR) applications is challenging where application developers are required to have expertise in the target VR technologies along with the problem domain expertise. New VR technologies impose a significant learning curve to even the most experienced VR developer. The proposed solution relies on synthesis to automate the migration of a VR application to a new unfamiliar VR platform/technology. To solve the problem, the Common Scene Definition Framework (CSDF) was developed, that serves as a superset/model representation of the target virtual world. Input modules were developed to populate the framework with the capabilities of the virtual world …

Generalization Issues In Pattern Classification Applied To Speaker Identification, Mame C. Sall

Electrical & Computer Engineering Theses & Dissertations

This thesis is an extension of previous work on speaker identification, but with a primary focus on the generalization performance of patterns classifiers for speaker identification. The goal for all pattern classifiers is to generalize to new data, not just perform well on the training data set. The error on the training data is typically a biased estimate of the generalization error. The training set error tends to be smaller than the generalization error if the model is selected such that it minimizes the training error. Therefore, the training error alone should not be used as a good predictor of …

Static And Modal Analysis Of The Magnetic Levitation Vehicle, Santosh Kumar Desetty

Mechanical & Aerospace Engineering Theses & Dissertations

The magnetic levitation train project at Old Dominion University has been stalled due to many technical problems. The control system is the main component of the vehicle, which is supposed to maintain an intended gap of 1 cm between the vehicle and the track while traveling, hence providing a smooth ride. The goal of the project is to document the mathematics of the complete system so that the control algorithm can be implemented and modified with the expectation of obtaining an improved levitation and propulsion.

The complete system includes the vehicle, the track, and the concrete guide-way. The focus of …

An Application And Evaluation Of A Methodology For Testing Operational Level Training Simulations, Karl Dean Neal

Computational Modeling & Simulation Engineering Theses & Dissertations

The Virginia Modeling, Analysis and Simulation Center has developed a methodology for testing operational-level training simulation systems. The methodology is built on analyses of the military tasks that an operational-level simulation is intended to train. These tasks are derived from the U.S. Department of Defense Universal Joint Task List. The methodology analyzes the categories of capabilities the simulation should have to support those tasks based on operational-level-military entities and actions. Cross-referencing the tasks and capabilities leads to functionality items the simulation should have. The methodology focuses on training joint force command tasks and decision making at the operational level of …

Modeling Multilevel Supply Chain Systems To Optimize Order Quantities And Order Points Through Mathematical Models, Discrete Event Simulation And Physical Simulations, Alok K. Verma

Mechanical & Aerospace Engineering Theses & Dissertations

Managing supply chains in today's distributed manufacturing environment has become more complex. To remain competitive in today's global marketplace, organizations must streamline their supply chains. The practice of coordinating the design, procurement, flow of goods, services, information and finances, from raw material flows to parts supplier to manufacturer to distributor to retailer and finally to consumer requires synchronized planning and execution. Efficient and effective supply chain management assists an organization in getting the right goods and services to the place needed at the right time, in the proper quantity and at acceptable cost. Managing this process involves developing and overseeing …

Quantifying Vulnerability To Critical Infrastructure, Barry Charles Ezell

Engineering Management & Systems Engineering Theses & Dissertations

Military and civilian leaders have the responsibility to protect our Nation's critical infrastructure, communities, and symbols of American power from terrorists, home and abroad, as well as from natural disasters. To this end, assessments are conducted to reduce vulnerability. The literature offers multiple definitions of vulnerability and measurement has not been adequately addressed. Thus, the purpose of this research has been to develop and deploy a systems-based model that quantifies vulnerability to critical infrastructure. This research defines critical infrastructure vulnerability as a measure of the susceptibility of critical infrastructure to threat scenarios. Vulnerability is a function of (1) threat scenario, …

Image Compression By Vector Quantization Of Dct Coefficients Using A Self-Organizing Neural Network, Kirankumar Boyapati

Electrical & Computer Engineering Theses & Dissertations

Image compression is used to remove different types of redundancies and irrelevant information in an image so that the space required for storing the image is minimized. Conventional transform based techniques remove the redundancies between adjacent pixels and irrelevant information in the image but fail to remove the redundancies between different parts of the image. There are techniques like vector quantization, which take care of the redundant information in different parts of the image, but fail to remove the irrelevant information in the image. In this thesis a new technique for lossy digital image compression is proposed which is a …

A Systems Methodology For Measuring Operational Organization Effectiveness: A Study Of The Original Equipment Computer Manufacturing Industry, 1948 To 2001, Teddy Steven Cotter

Engineering Management & Systems Engineering Theses & Dissertations

Optimizing operational organizational effectiveness is the central, although often unstated, goal of engineering management and systems engineering research and applications. Two fundamental problems remain to be addressed in pursuit of this goal. First, despite over fifty years of research in various disciplines, there is still no universally accepted definition of organizational effectiveness. Second, no methodology exists to identify the domains, dimensions, and determinants of operational organizational effectiveness and dynamically model operational organizational effectiveness within a given population.

This research synthesizes a systems engineering methodology for identifying the domains, dimensions, and determinants of and dynamically modeling operational organizational effectiveness for an …

Applying A Simulation-Based Real-Time Decision Making Method To Mass Casualty Scenarios In Hospital Emergency Departments, Fatemah Al-Douli

Electrical & Computer Engineering Theses & Dissertations

The high possibility of having a mass casualty incident compels hospitals to plan ahead in order to sufficiently provide the healthcare needed to as many casualty victims as possible. The Emergency Rooms (ER) are usually hospitals' main entrance for many casualties. Therefore, the ER in the Children's Hospital of the King's Daughters (CHKD) was selected as the system to be examined. The ER in CHKD, the only specialized pediatric ER in the region, already struggles to handle very high patient arrival rates. Consequently, it is expected that treating a large number of patients surviving within a very short period of …

Lightweight Federation Of Non-Cooperating Digital Libraries, Rong Shi

Computer Science Theses & Dissertations

This dissertation studies the challenges and issues faced in federating heterogeneous digital libraries (DLs). The objective of this research is to demonstrate the feasibility of interoperability among non-cooperating DLs by presenting a lightweight, data driven approach, or Data Centered Interoperability (DCI). We build a Lightweight Federated Digital Library (LFDL) system to provide federated search service for existing digital libraries with no prior coordination.

We describe the motivation, architecture, design and implementation of the LFDL. We develop, deploy, and evaluate key services of the federation. The major difference to existing DL interoperability approaches is one where we do not insist on …

Shape Memory Alloy Applications On Control Of Thermal Buckling, Panel Flutter And Random Vibration Of Composite Panels, Xinyun Guo

Mechanical & Aerospace Engineering Theses & Dissertations

Shape Memory Alloy (SMA) has a unique ability to recover large prestrain (up to 8∼10% elongation for Nitinol, a typical SMA material) completely when the alloy is heated (e.g. aerodynamic heating) above the austenite finish temperature Af. An innovative concept is to utilize the large recovery stress by embedding the prestrained SMA in a traditional fiber-reinforced laminated composite plate, which is called SMA hybrid composite (SMAHC) plate. In this research, static thermal and aerothermal deflections, dynamic panel flutter and random response are investigated for traditional composite plates and SMAHC plates under combined aerodynamic, random and thermal loads by employing nonlinear …

Clustering And Hybrid Routing In Mobile Ad Hoc Networks, Lan Wang

Computer Science Theses & Dissertations

This dissertation focuses on clustering and hybrid routing in Mobile Ad Hoc Networks (MANET). Specifically, we study two different network-layer virtual infrastructures proposed for MANET: the explicit cluster infrastructure and the implicit zone infrastructure. In the first part of the dissertation, we propose a novel clustering scheme based on a number of properties of diameter-2 graphs to provide a general-purpose virtual infrastructure for MANET. Compared to virtual infrastructures with central nodes, our virtual infrastructure is more symmetric and stable, but still light-weight. In our clustering scheme, cluster initialization naturally blends into cluster maintenance, showing the unity between these two operations. …

Design And Implementation Of One And Two-Degree-Of-Freedom Magnetic Suspension And Balance Systems, Mark W. Adams

Electrical & Computer Engineering Theses & Dissertations

The main objectives of this research were to design and implement one and two-degree-of-freedom (1 DOF and 2-DOF) magnetic levitation systems to levitate permanent magnet cores contained in PVC pipes, 8.4 cm and 76.2 cm in length, respectively. This project used the components of a Magnetic Suspension and Balance System (MSBS) that is being built to provide obstruction free positioning of test models in six degrees of freedom (6-DOF) inside the Princeton University/Office of Naval Research High Reynolds Number Test Facility (HRTF). The HRTF, a specialized wind tunnel designed to simulate undersea conditions by creating a low-speed, 3500 PSI air …

Carbon Nanotubes And Tungsten Oxide Nanorods: Synthesis And Applications, Bing Xiao

Electrical & Computer Engineering Theses & Dissertations

Synthesis and applications of two types of one-dimensional nanomaterials, carbon nanotubes (CNTs) and tungsten oxide nanorods, are investigated in this dissertation. Multi-walled CNTs have been successfully synthesized using two types of chemical vapor deposition (CVD) methods: microwave plasma enhanced CVD and atmospheric pressure thermal CVD. CNTs and their synthesis processes are characterized with various analysis techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and optical emission spectroscopy. Ultra-thin and high quality multi-walled CNTs are discovered in CNT films produced by MPCVD, which exhibit good field emission performance that is found to be dependent on the synthesis …

High Power 121.6 Nm Radiation Source For Advanced Lithography, Jianxun Yan

Electrical & Computer Engineering Theses & Dissertations

A novel high power 121.6 nm radiation source based on dielectric barrier discharge (DBD) has been developed for advanced lithography applications. The discharge unit consists basically of a hollow tube made of a dielectric material with two loop-electrodes wrapped on the outside of the tube. The discharge is generated inside the tube by means of a 13.56 MHz RF power system. The discharge unit is located in a vacuum chamber that provides a dynamic gas flow and windows for radiation transmission.

A very intense and spectrally clean Lyman-α line at 121.6 nm was observed by operating the DBD discharge in …

C2iedm For The Gig: A Tutorial, Andreas Tolk, Charles Turnitsa, Curtis Blais

Computational Modeling & Simulation Engineering Faculty Publications

No abstract provided.

Modeling Of Commercial Maritime Port Recoverability From Security Disruptions: Work-In-Progress, C. Ariel Pinto, Wayne K. Talley

Engineering Management & Systems Engineering Faculty Publications

This article describes active research in commercial maritime port's recovery from security disruptions which explores the synergy of economic and simulation models in investigating the recoverability of ports after security incidents. Previous study has identified decision variables and throughput simulation models of port operation. However, none of these models have been utilized to investigate port's recovery from a security disruption and in evaluating recoverability investments. The method of research includes analysis of recorded disruptions, identification of impediments to recovery and investment criteria for recoverability. This article provides managers insight into including security and continuity of operation in managing various types …

Software Development Project Risk Management: A Literature Review, Kevin Macg. Adams, C. Ariel Pinto

Engineering Management & Systems Engineering Faculty Publications

The rapid and unprecedented growth in software has brought with it some of the most spectacular and costly project failures in modern history. How risk management is presented in the scholarly journals may give insight into the risk management methods and techniques in use on software development projects. This paper provides a glimpse into the risk management methods, methodologies and techniques available to those who are responsible for software development projects by conducting a non-experimental content analysis. The findings reveal that risk management has not received sufficient attention and does not appear to be widely accepted within the software engineering …

Managing The Transformation Of System Of Systems Engineering, Samuel F. Kovacic, Andres Sousa-Poza

Engineering Management & Systems Engineering Faculty Publications

SOSE methodologies exist that support engineering difficult and disparate systems with a technical solution. However, from literature it is apparent that there is a need for a formal methodology and methods that govern engineering of System of Systems (SOS) beyond the technical solution. This paper presents some of the current thinking being undertaken at NCSOSE (National Centers for Systems of Systems Engineering), on what is driving the development of SOSE, and a hypothesized solution to this problem. The purpose is to offer a different approach for resolving complexity within a situation. The paper concludes with an initial derivative of a …

Individual Certification As An Engineering Manager?, Rafael Landaeta, Kawintorn Pothanun, William Peterson

Engineering Management & Systems Engineering Faculty Publications

Several of the discipline specific professional societies are offering or planning to offer certification of individuals as engineering managers. Does this have implications for Engineering Management programs at universities? Other stakeholders (faculty, students, employers, and graduates of engineering management programs) are impacted by certification as well. This paper attempts to look at the issue from several points of view. This paper is intended to provoke a dialog on the topic.

Development Of A System Of Systems Engineering Method, Ji Hyon Mun, Morgan Henrie, Yaneth Correa, Charles Keating, Andres Sousa-Poza

Engineering Management & Systems Engineering Faculty Publications

Systems engineers have been facing challenges with the design and analysis of multiple complex systems. System of Systems Engineering has emerged to assist in this challenge with the systemic analysis, design, and transformation of complex metasystems. This paper outlines a proposed method to overcome these challenges, which is grounded in System of Systems Engineering principles and methodology. An overview of System of Systems Engineering will be provided for understanding of its significance and the attempt to complement Systems Engineering efforts in dealing with the aforementioned challenges. Finally, discussion on the proposed method, with respect to complex system analysis, is provided.

A Comparison Of The Canons Of Science Used In Positivistic Research And Constructivist/Naturalistic Research, Ipek Bozkurt, Andres Sousa-Poza

Engineering Management & Systems Engineering Faculty Publications

In this paper, the canons of science which are crucial for positivistic, empirical research and constructivist/naturalistic research will be identified, described, compared and discussed. Although there are common canons which are often used in papers throughout literature, it would be beneficial to set a common ground for the identification and use of the canons. The canons used in positivistic research will differ from the canons used in constructivist/ naturalistic research. This paper will analyze major publications (papers, books, etc.) exploring the canons either directly or indirectly, and will provide a link between major characteristics of two different research philosophies and …

Production Research In China, S. Chaudhry, S. Feng, H. Li, H. Sui, J. L. Zhang, Z Zhang, Li Xu

Information Technology & Decision Sciences Faculty Publications

(First paragraph) China is the world’s largest emerging economy. In recent years, China has moved to an increasingly market-oriented economy that opens to international trade and investment. At the same time, the popularity of China as a manufacturing base, assembling goods for sale worldwide is growing. In addition to global manufacturers who have built their own plants in China, many manufacturing companies are outsourcing production to Chinese subcontractors and branding the products with their own logos. In today’s China, production research is becoming more and more important; advanced production research becomes an important enabler to make its manufacturing industry competitive. …

Selective Field Effects On Intracellular Vacuoles And Vesicle Membranes With Nanosecond Electric Pulses, Ephrem Tekle, Hammou Oubrahim, Sergey M. Dzekunov, Juergen F. Kolb, Karl H. Schoenbach

Bioelectrics Publications

Electric pulses across intact vesicles and cells can lead to transient increase in permeability of their membranes. We studied the integrity of these membranes in response to external electric pulses of high amplitude and submicrosecond duration with a primary aim of achieving selective permeabilization. These effects were examined in two separate model systems comprising of 1), a mixed population of 1,2-di-oleoyl-sn-glycero-3-phosphocholine phospholipid vesicles and in 2), single COS-7 cells, in which large endosomal membrane vacuoles were induced by stimulated endocytosis. It has been shown that large and rapidly varying external electric fields, with pulses shorter than the charging time of …

Predicted Properties Of Microhollow Cathode Discharges In Xenon, J. P. Boeuf, L. C. Pitchford, K. H. Schoenbach

Bioelectrics Publications

A fluid model has been developed and used to help clarify the physical mechanisms occurring in microhollow cathode discharges (MHCD). Calculated current-voltage (I-V) characteristics and gas temperatures in xenon at 100 Torr are presented. Consistent with previous experimental results in similar conditions, we find a voltage maximum in the I-V characteristic. We show that this structure reflects a transition between a low-current, abnormal discharge localized inside the cylindrical hollow cathode to a higher-current, normal glow discharge sustained by electron emission from the outer surface of the cathode. This transition, due to the geometry of …

Simulations Of Nanopore Formation And Phosphatidylserine Externalization In Lipid Membranes Subjected To A High-Intensity, Ultrashort Electric Pulse, Q. Hu, R. P. Joshi, K. H. Schoenbach

Bioelectrics Publications

A combined MD simulator and time dependent Laplace solver are used to analyze the electrically driven phosphatidylserine externalization process in cells. Time dependent details of nanopore formation at cell membranes in response to a high-intensity (100kV∕cm), ultrashort (10ns) electric pulse are also probed. Our results show that nanosized pores could typically be formed within about 5ns. These predictions are in very good agreement with recent experimental data. It is also demonstrated that defect formation and PS externalization in membranes should begin on the anode side. Finally, the simulations confirm that PS externalization is a nanopore facilitated event, rather than the …

Halonitromethane Treatment Using Advanced Oxidation Process: Rates, Mechanisms And Kinetic Modeling, Stuart Kirkham Cole

Civil & Environmental Engineering Theses & Dissertations

Halonitromethanes (HNMs) are low molecular weight halogenated disinfection-by-products (DBPs) found to be formed during ozonation, chlorination, or chloramination of waters containing natural bromide ion and nitrogenous organic matter. This work identifies the absolute rate constants for the oxidative hydroxyl radical (•OH) and reductive hydrated electron e^- _aq extinction of HNM compounds. Three forms of HNMs included in this study are the chlorinated, brominated, and mixed halogenated compounds. Electron pulse radiolysis and transient absorption spectroscopy were used to measure •OH and e^- _aq radical absolute reaction rate constants for a total of nine HNMs. To elucidate the decomposition reaction …